1. Field of the Invention
The instant invention relates generally to the field of pressurized fluid systems and more specifically it relates to an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system. The purpose of the apparatus is to provide the technician with a simple method of injecting a predetermined amount of a secondary fluid, e.g., a fluorescent dye, and/or lubricant into a pressurized system.
2. Description of the Prior Art
Numerous pressurized fluid systems have been provided in the prior art that are adapted to operate optimally within a certain pressure range. If the internal pressure falls below this range, the system needs to be recharged with an appropriate lubricant. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.
There does not presently exist a cost effective way to accomplish the task of inserting a predetermined amount of lubricant into a pressurized system. Added to this, is the fact that when a technician arrives on site they are faced with a myriad number of systems with service connection access ranging from the accessible to the acrobatic and often cramped working conditions.
Some systems contain a combination of fluids. For example, air conditioning and refrigeration systems generally contain a refrigerant (the primary fluid) in combination with a lubricating oil (the secondary fluid) for the compressor and other critical components. The lubricating oil is generally present in fairly low quantities, usually less than 5% of the total fluid. The present invention provides for the introduction of these and other secondary fluids into air conditioning or refrigeration systems charged with the primary fluids in order to detect leaks in the pressurized systems.
Furthermore, air conditioning or refrigeration system leaks are difficult to locate because refrigerants are generally odorless and colorless gases. The present invention provides for a device and method for injecting a small amount of a concentrated fluorescent additive or dye into the system, thereby making the leaks easier to find. The fluorescent dye can be injected into the system with the present device or they can be placed in the systems at the original equipment manufacturing facility prior to the system being put into service. These air conditioning and refrigeration systems are closed loop recirculating systems and the secondary fluid is a lubricant that also travels throughout the system while in operation. The dye will travel throughout the system and leak out with the refrigerant. The dye will leave a stain that can be further enhanced with the use of an ultraviolet (UV) lamp. The UV wavelength of light will excite the dye allowing the operator to more easily identify the exact location of the leak. The device can also be used to add the appropriate lubricant to the air conditioning or refrigeration system without stopping the system and without any special equipment.
A cartridge that is at or about atmospheric pressure while not in use contains the concentrated fluorescent dye and/or lubricant. The cartridge is connected to the device of the present invention in way that will raise the pressure of the dye above that of the operating system. The connection between the device and the operating system must be airtight. The connection can be a quick coupler, thread or other means of positive, sealed connection.
The preferred embodiment of the present invention is for an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system and includes an injection device with a receptacle portion for receiving a disposable or reusable lubricant canister and a connector assembly for attaching the lubricant canister to the pressurized system. The lubricant canister contains lubricant and/or fluorescent dye. It is a further aim of the present invention not to limit the mechanical means of lubricant and/or fluorescent dye delivery just to hand pressure, but to provide other embodiments using various types of hand tools and structures to accomplish the delivery of the lubricant and/or fluorescent dye to the pressurized system.
More specifically, the present invention is for an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system, comprising a canister containing a second fluid, where the secondary fluid comprises a fluorescent dye; means for fluidly coupling the canister to the pressurized system; and means for forcing the secondary fluid out of the canister, through the fluidly coupling means and into a service valve of the pressurized system.
In a preferred embodiment, the canister includes a tubular casing for holding the secondary fluid therein; a threaded nozzle integral with and extending out from a first end of the tubular casing to engage with one end of the fluidly coupling means; and a piston inserted within an open second end of the tubular casing to engage with a secondary fluid forcing means.
In a more preferred embodiment, the tubular casing is fabricated out of transparent material and includes a plurality of gradient markings to aid in accurately dispensing a predetermined amount of the secondary fluid therefrom. In another embodiment, the canister further includes a threaded cap, to engage with the threaded nozzle when the canister is not in use, so as to prevent leakage of the secondary fluid through the threaded nozzle.
In another preferred embodiment, the fluidly coupling means is a connector assembly having a first end connected to the threaded nozzle of the canister and a second end connected to the service valve of the pressurized system. In a more preferred embodiment, the connector assembly includes a flexible conduit; a thread on the first end of the flexible conduit, to engage with the threaded nozzle of the canister; and a release valve on a second end of the flexible conduit, to engage with the service valve of the pressurized system.
In another preferred embodiment, the connector assembly further includes a one-way check valve at the first end of the flexible conduit, which prevents any material from back flushing into and contaminating the secondary fluid in the canister.
In yet another preferred embodiment, the release valve includes a closeable valve, which prevents any material from back flushing into the flexible conduit from the service valve of the pressurized system, and to allow the release valve to disconnect from the service valve of the pressurized system, to prevent leakage of the secondary fluid therefrom.
In more preferred embodiments, the release valve includes a snap lock fitting to engage with the service valve of the pressurized system or includes a threaded fitting to engage with the service valve of the pressurized system.
In another more preferred embodiment, the secondary fluid forcing means is an injection device. In yet another more preferred embodiment, the injection device includes a housing having a receptacle portion to receive the canister therein; and a drive mechanism to force the piston into the tubular casing, to cause the secondary fluid to exit the threaded nozzle through the fluidly coupling means, past the service valve, and into the pressurized system.
In another preferred embodiment, the drive mechanism includes a hand grip integral with and extending downwardly on the housing; a trigger pivotally mounted to the housing adjacent the hand grip; a central drive shaft extending longitudinally through the housing and transversely past a pivotal portion of the trigger; a cylindrical head on an inner end of the central drive shaft, to engage with the piston of the canister; a first pawl spring biased on the central drive shaft forward the pivotal portion of the trigger; and a second pawl spring biased on the central drive shaft rearward the pivotal portion of the trigger, the second pawl having a tongue extending out through a rear wall of the housing above the hand grip, so that when the trigger is squeezed, the first pawl will move into contact with the central drive shaft, to push the central drive shaft forward with the cylindrical head making contact with the piston, while the second pawl prevents reverse movement of the central drive shaft, until the tongue disengages the second pawl, allowing the central drive shaft to be pulled back to a desired position.
In a more preferred embodiment, the drive mechanism includes a hand grip integral with and extending downwardly on the housing; a trigger pivotally mounted to the housing adjacent the hand grip; a central drive shaft extending longitudinally through the housing and transversely above a pivotal portion of the trigger, the central drive shaft having a plurality of teeth extending therealong; a cylindrical head on an inner end of the central drive shaft, to engage with the piston of the canister; and a pawl pivotally mounted between the pivotal portion of the trigger and the housing, so that when the trigger is squeezed, the pawl will move into contact with the teeth on the central drive shaft, to push the central drive shaft forward with the cylindrical head making contact with the piston.
In another more preferred embodiment, the drive mechanism includes a second pawl spring biased in the housing to make contact with the teeth on the central drive shaft forward the first pawl, to prevent reverse movement of the central drive shaft.
In yet another more preferred embodiment, the drive mechanism includes a stationary nut mounted vertically within a rear wall of the housing; an elongated threaded rod extending longitudinally through the stationary nut; a cylindrical head on an inner end of the elongated threaded rod, to engage with the piston of the canister; and means on an outer end of the elongated threaded rod for rotating the elongated threaded rod through the stationary nut and moving the elongated threaded rod with the cylindrical head forward, to make contact with the piston.
In another preferred embodiments, the rotating means is a bolt head which can be turned by an open end and box wrench, is a socket head which can be turned by a ratchet socket wrench or is a handle rod extending transversely through the outer end of the elongated threaded rod which can be turned by a hand of a person.
In another preferred embodiment, the drive mechanism includes a rear chamber formed within the housing and having an inlet port to allow compressed gas to enter the rear chamber; a central drive shaft carried longitudinally within the tubular casing of the canister; a cylindrical head on an inner end of the central drive shaft, to engage with the piston; and a transverse drive plate on an outer end of the central drive shaft within the tubular casing adjacent the rear chamber, so that when the compressed gas is introduced through the inlet port into the rear chamber, the transverse drive plate will push the central drive shaft forward with the cylindrical head to make contact with the piston.
The present invention also discloses a canister or cartridge for charging a closed, pressurized air conditioning or refrigeration system with a fluid. The cartridge comprises a closed, non-pressurized cylindrical cartridge, where the cartridge has two ends, a first open end and a second open end, where the first open end comprises an inner nozzle which connects to the system being charged and an outer nozzle; a predetermined amount of the fluid; and a piston sealably disposed with the second open end of the cartridge, where the cartridge is adapted to connect sealably and releasably to the pressurized air conditioning or refrigeration system to form a closed binary system.
In a preferred embodiments of the cartridge, the fluid comprises a lubricant for the air conditioning or refrigeration systems; the fluid comprises a fluid dye for the air conditioning or refrigeration systems; or the fluid comprises a lubricant and a fluid dye for the air conditioning or refrigeration systems.
In other preferred embodiments of the cartridge, the fluid is maintained in the cartridge at about ambient pressure; and/or the cartridge is fabricated out of transparent material and includes a plurality of gradient markings.
In yet other preferred embodiments of the cartridge, the inner nozzle is surrounded by an internal thread; the outer nozzle is surrounded by an external thread; the outer nozzle comprises a threaded cap for engagement with the external thread; and/or the inner nozzle is surrounded by an internal thread and the outer nozzle is surrounded by an external thread.
In still other preferred embodiments of the cartridge, the piston further comprises an O-ring; or the piston further comprises a recessed double O-ring.
The present invention also discloses a method for detecting leaks in a pressurized air conditioning or refrigeration system. The method comprises the steps of charging the pressurized air conditioning or refrigeration system with a fluorescent dye with the apparatus of the present invention; inspecting the pressurized air conditioning or refrigeration system for leaks of the fluorescent dye from the pressurized air conditioning or refrigeration system; and detecting any leaks in the pressurized air conditioning or refrigeration system. In a preferred embodiment, the inspecting is done with ultraviolet light.
Thus, a primary object of the present invention is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that will overcome the shortcomings of the prior art devices.
Another object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that will allow a technician to inject a predetermined amount of lubricant and/or fluorescent dye into the pressurized system.
It is yet a further object of the invention to provide a method and apparatus for charging a pressurized air conditioning/refrigeration line with a lubricant and/or fluorescent dye from a closed, non-pressurized charging cartridge containing a predetermined amount of such lubricant and/or fluorescent dye.
An additional object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system which can be readily carried to a site, be easily operated, and can deliver a measured amount of lubricant and/or fluorescent dye into the pressurized system.
A further object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that is simple and easy to use.
A still further object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that is economical in cost to manufacture.
It is yet a further object to present an apparatus and method for detecting leaks in air conditioning or refrigeration systems by injecting a fluorescent dye into the systems and then inspecting the system for leaks of the fluorescent dye from the systems.
Further objects of the invention will appear as the description proceeds.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.